When Horsting retired as regional president and executive vice president in 2024, hundreds of former employees, clients, trade partners and even competitors gathered to honor his impact on the company, on the projects he led, on the construction industry and on the communities where he worked. Those projects included work for school districts, health care providers, civic institutions and other organizations.

As a young man, Horsting says he entered the industry with an eye on earning a good paycheck, but he discovered that the satisfaction of building projects that improved communities motivated him throughout his 42-year career at AP.

“You get to see the finished project. If it’s a hospital, you get to see it being used, if it’s a rec center, you see the kids playing, if it’s a school, you watch the kids go to a school where they’re learning,” Horsting says. “It’s really fun to see the stuff you got to build and how the community uses and enjoys it.”

The Lucille Erwin Middle School in Loveland, Colo., was delivered in 12 months under Horsting’s leadership. The project put Adolfson & Peterson on the map for K-12 education construction.
Photo courtesy of Adolfson & Peterson

Making an Impact

Brandon Hill, vice president of operations for AP, says Horsting made a strong impression on him on his first day as an intern 30 years ago when he found Horsting in the middle of a concrete pour working alongside the crew.

“At that time, I did not think much of it, but I quickly understood that Tommy was always willing to roll up his sleeves and get right in the middle of the work, assist his people, help solve issues—whatever it takes for everyone to be successful,” Hill says.

Horsting brought a can-do philosophy to every project he led, fostering contractor-owner partnerships that have lasted decades, Hill says. On the Kaiser Franklin Medical Office Building in Denver, the firm reports that Horsting’s collaborative approach laid the groundwork for a 30-year relationship that has included 11 projects with the health care provider. On the University of Northern Colorado’s Ross Hall project in Greeley, Colo., Horsting paired innovation with transparent communication, helping establish the company’s presence in higher education construction.

Horsting cites the Lucille Erwin Middle School as a career milestone because it put AP on the map for K-12 construction. While school projects typically require 12 months for design and another 12 months for construction, the district wanted the 160,000-sq-ft school designed and built in a single year.

“I was young and dumb. So I said, ‘Sure, we can do that, right?’” Horsting says.

“That was a real team effort by everybody,” he adds. “We all worked around the clock to make this thing happen. And so that was really a stepping stone for the company. That really was when we started to become known as the biggest school builder in the state of Colorado.”

During his tenure, Horsting personally led more than $1.9 billion in completed work across K-12, higher education, health care, civic and commercial markets. His relationship-driven leadership helped the company expand into new sectors—including the national mission-critical market shortly before his retirement—when he secured a $145-million multistate expansion project for a confidential repeat client.

When asked what he is most proud of, Horsting points to the people he mentored and developed, many of whom helped smooth the company’s leadership transition when he retired.

“I hired and developed a team of people that took this company over when I left, and we didn’t miss a beat,” Horsting says. “The guys and gals I hired as engineers, laborers, carpenters [are all now] in leadership roles, doing the same thing I did.”

Hill praises Horsting’s ability to recognize talent even before individuals see it themselves.

“Tommy is not the type to sit down and have formal check-ins,” Hill says. “His style is always developing individuals through communication, stretching their abilities with new opportunities while keeping an eye on them to make sure that they succeed. It was never about him being successful; it was always about his people being successful.”

Even during economic downturns, Horsting encouraged company leadership to find work rather than resort to layoffs. “We’re responsible for 300 families, not 300 employees,” Horsting says.

That people-first mindset became central to the company’s culture. Maintaining a family atmosphere grew more challenging as the firm expanded, but Horsting remained intentional about bringing people together through company picnics, baseball outings, holiday parties and leadership visits to jobsites.

Horsting’s commitment to relationships extended beyond the jobsite. He served on the boards of the Metro Denver Economic Development Corp. and the Associated General Contractors of Colorado. Each December, he arrived at AP’s office with his pickup truck loaded with toys, food and gifts for families in need, supporting the holiday giving campaigns he founded decades earlier.

Today, AP continues to thrive, built on a foundation of stability, collaboration and opportunity. The company’s average employee tenure of 10 years is more than double the industry average of four years.

Hill describes Horsting as a from-the-ground-up success story.

“He’s someone that started out in this industry in the trades and continued to carve his path and grow into the president of an entire region,” Hill says. “His advocacy has always been to build that next person into the next leader and to help carve that career path for that individual and his family—the opportunity for anyone at any level to grow into whatever they desire.”

In retirement, Horsting continues to serve as a strategic client adviser for AP.